Protein Information Resource, Georgetown University Medical Center, WA 20007, USA, Center for Bioinformatics and Computational Biology, University of Delaware, Newark, DE 19711, USA, Department of Bioinformatics and Computational Biology, The Jackson Laboratory, Bar Harbor, ME 04609, USA, Department of Biochemistry and Molecular Pharmacology, NYU School of Medicine, NY 10016, USA, Department of Neurology, University at Buffalo School of Medicine and Biomedical Sciences, Buffalo, NY 14203, USA, Center of Excellence in Bioinformatics and Life Sciences, University at Buffalo, Buffalo, NY 14203, USA, Department of Immunology, Duke University Medical Center, Durham, NC 27705, USA and Department of Oral Diagnostic Sciences, University at Buffalo School of Dental Medicine, Buffalo, NY 14214, USA.

Abstract

The Protein Ontology (PRO; http://proconsortium.org) formally defines protein entities and explicitly represents their major forms and interrelations. Protein entities represented in PRO corresponding to single amino acid chains are categorized by level of specificity into family, gene, sequence and modification metaclasses, and there is a separate metaclass for protein complexes. All metaclasses also have organism-specific derivatives. PRO complements established sequence databases such as UniProtKB, and interoperates with other biomedical and biological ontologies such as the Gene Ontology (GO). PRO relates to UniProtKB in that PRO's organism-specific classes of proteins encoded by a specific gene correspond to entities documented in UniProtKB entries. PRO relates to the GO in that PRO's representations of organism-specific protein complexes are subclasses of the organism-agnostic protein complex terms in the GO Cellular Component Ontology. The past few years have seen growth and changes to the PRO, as well as new points of access to the data and new applications of PRO in immunology and proteomics. Here we describe some of these developments.

Cytoscape view of BUB1:BUB1B complexes. The is_a relationship between child and parent in the PRO hierarchy and the has_component relationship between complexes and their components are shown by black arrows and blue dotted arrows, respectively. Clicking on a node (e.g. frog-BUB1B/Phos:2) brings a pop-up box that provides details and allows additional actions. Only a subset of nodes is shown, which have been rearranged for clarity.